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    Annotation of /trunk/mkinitrd-magellan/klibc/usr/kinit/ipconfig/packet.c

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    Revision 1297 - (hide annotations) (download)
    Fri May 27 15:12:11 2011 UTC (12 years, 11 months ago) by niro
    File MIME type: text/plain
    File size: 5579 byte(s) 
    -updated to klibc-1.5.22 with mntproc definitions patch included
    1 niro 532 /*
    2     * Packet socket handling glue.
    3     */
    4     #include <sys/types.h>
    5     #include <sys/socket.h>
    6     #include <stdio.h>
    7     #include <stdlib.h>
    8     #include <string.h>
    9     #include <unistd.h>
    10     #include <net/if_packet.h>
    11     #include <netinet/if_ether.h>
    12     #include <netinet/in.h>
    13     #include <netpacket/packet.h>
    14     #include <asm/byteorder.h>
    15     #include <arpa/inet.h>
    16     #include <netinet/ip.h>
    17     #include <netinet/udp.h>
    18    
    19     #include "ipconfig.h"
    20     #include "netdev.h"
    21     #include "packet.h"
    22    
    23     static int pkt_fd = -1;
    24    
    25     uint16_t cfg_local_port = LOCAL_PORT;
    26     uint16_t cfg_remote_port = REMOTE_PORT;
    27    
    28     int packet_open(void)
    29     {
    30     int fd, one = 1;
    31    
    32     if (pkt_fd != -1)
    33     return pkt_fd;
    34    
    35     /*
    36     * Get a PACKET socket for IP traffic.
    37     */
    38     fd = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
    39     if (fd == -1) {
    40     perror("socket");
    41     return -1;
    42     }
    43    
    44     /*
    45     * We want to broadcast
    46     */
    47 niro 815 if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one,
    48     sizeof(one)) == -1) {
    49 niro 532 perror("SO_BROADCAST");
    50     close(fd);
    51     fd = -1;
    52     }
    53    
    54     pkt_fd = fd;
    55    
    56     return fd;
    57     }
    58    
    59     void packet_close(void)
    60     {
    61     close(pkt_fd);
    62     pkt_fd = -1;
    63     }
    64    
    65     static unsigned int ip_checksum(uint16_t *hdr, int len)
    66     {
    67     unsigned int chksum = 0;
    68    
    69     while (len) {
    70     chksum += *hdr++;
    71     chksum += *hdr++;
    72     len--;
    73     }
    74     chksum = (chksum & 0xffff) + (chksum >> 16);
    75     chksum = (chksum & 0xffff) + (chksum >> 16);
    76     return (~chksum) & 0xffff;
    77     }
    78    
    79     struct header {
    80     struct iphdr ip;
    81     struct udphdr udp;
    82     } __attribute__ ((packed));
    83    
    84     static struct header ipudp_hdrs = {
    85     .ip = {
    86     .ihl = 5,
    87     .version = IPVERSION,
    88     .frag_off = __constant_htons(IP_DF),
    89     .ttl = 64,
    90     .protocol = IPPROTO_UDP,
    91     .saddr = INADDR_ANY,
    92     .daddr = INADDR_BROADCAST,
    93     },
    94     .udp = {
    95     .source = __constant_htons(LOCAL_PORT),
    96     .dest = __constant_htons(REMOTE_PORT),
    97     .len = 0,
    98     .check = 0,
    99     },
    100     };
    101    
    102 niro 1122 #ifdef DEBUG /* Only used with dprintf() */
    103 niro 532 static char *ntoa(uint32_t addr)
    104     {
    105     struct in_addr in = { addr };
    106     return inet_ntoa(in);
    107     }
    108 niro 1122 #endif /* DEBUG */
    109 niro 532
    110     /*
    111 niro 1122 * Send a packet. The options are listed in iov[1...iov_len-1].
    112 niro 532 * iov[0] is reserved for the bootp packet header.
    113     */
    114     int packet_send(struct netdev *dev, struct iovec *iov, int iov_len)
    115     {
    116     struct sockaddr_ll sll;
    117 niro 1122 struct msghdr msg;
    118 niro 532 int i, len = 0;
    119    
    120 niro 1122 memset(&sll, 0, sizeof(sll));
    121     msg.msg_name = &sll;
    122     msg.msg_namelen = sizeof(sll);
    123     msg.msg_iov = iov;
    124     msg.msg_iovlen = iov_len;
    125     msg.msg_control = NULL;
    126     msg.msg_controllen = 0;
    127     msg.msg_flags = 0;
    128    
    129 niro 532 if (cfg_local_port != LOCAL_PORT) {
    130     ipudp_hdrs.udp.source = htons(cfg_local_port);
    131     ipudp_hdrs.udp.dest = htons(cfg_remote_port);
    132     }
    133    
    134 niro 1122 dprintf("\n udp src %d dst %d", ntohs(ipudp_hdrs.udp.source),
    135     ntohs(ipudp_hdrs.udp.dest));
    136 niro 532
    137 niro 1122 dprintf("\n ip src %s ", ntoa(ipudp_hdrs.ip.saddr));
    138     dprintf("dst %s ", ntoa(ipudp_hdrs.ip.daddr));
    139 niro 532
    140     /*
    141     * Glue in the ip+udp header iovec
    142     */
    143     iov[0].iov_base = &ipudp_hdrs;
    144     iov[0].iov_len = sizeof(struct header);
    145    
    146     for (i = 0; i < iov_len; i++)
    147     len += iov[i].iov_len;
    148    
    149     sll.sll_family = AF_PACKET;
    150     sll.sll_protocol = htons(ETH_P_IP);
    151     sll.sll_ifindex = dev->ifindex;
    152     sll.sll_hatype = dev->hwtype;
    153     sll.sll_pkttype = PACKET_BROADCAST;
    154     sll.sll_halen = dev->hwlen;
    155     memcpy(sll.sll_addr, dev->hwbrd, dev->hwlen);
    156    
    157     ipudp_hdrs.ip.tot_len = htons(len);
    158     ipudp_hdrs.ip.check = 0;
    159     ipudp_hdrs.ip.check = ip_checksum((uint16_t *) & ipudp_hdrs.ip,
    160     ipudp_hdrs.ip.ihl);
    161    
    162     ipudp_hdrs.udp.len = htons(len - sizeof(struct iphdr));
    163    
    164 niro 1122 dprintf("\n bytes %d\n", len);
    165 niro 532
    166     return sendmsg(pkt_fd, &msg, 0);
    167     }
    168    
    169 niro 1297 void packet_discard(struct netdev *dev)
    170 niro 532 {
    171     struct iphdr iph;
    172     struct sockaddr_ll sll;
    173     socklen_t sllen = sizeof(sll);
    174    
    175 niro 1297 sll.sll_ifindex = dev->ifindex;
    176    
    177 niro 815 recvfrom(pkt_fd, &iph, sizeof(iph), 0,
    178     (struct sockaddr *)&sll, &sllen);
    179 niro 532 }
    180    
    181     /*
    182     * Receive a bootp packet. The options are listed in iov[1...iov_len].
    183     * iov[0] must point to the bootp packet header.
    184 niro 1122 * Returns:
    185 niro 1297 * -1 = Error, try again later
    186     * 0 = Discarded packet (non-DHCP/BOOTP traffic)
    187 niro 1122 * >0 = Size of packet
    188 niro 532 */
    189 niro 1297 int packet_recv(struct netdev* dev, struct iovec *iov, int iov_len)
    190 niro 532 {
    191     struct iphdr *ip, iph;
    192     struct udphdr *udp;
    193     struct msghdr msg = {
    194     .msg_name = NULL,
    195     .msg_namelen = 0,
    196     .msg_iov = iov,
    197     .msg_iovlen = iov_len,
    198     .msg_control = NULL,
    199     .msg_controllen = 0,
    200     .msg_flags = 0
    201     };
    202     int ret, iphl;
    203 niro 1297 struct sockaddr_ll sll;
    204     socklen_t sllen = sizeof(sll);
    205 niro 532
    206 niro 1297 sll.sll_ifindex = dev->ifindex;
    207     msg.msg_name = &sll;
    208     msg.msg_namelen = sllen;
    209    
    210 niro 532 ret = recvfrom(pkt_fd, &iph, sizeof(struct iphdr),
    211 niro 1297 MSG_PEEK, (struct sockaddr *)&sll, &sllen);
    212 niro 532 if (ret == -1)
    213 niro 1297 return -1;
    214 niro 532
    215     if (iph.ihl < 5 || iph.version != IPVERSION)
    216     goto discard_pkt;
    217    
    218     iphl = iph.ihl * 4;
    219    
    220     ip = malloc(iphl + sizeof(struct udphdr));
    221     if (!ip)
    222     goto discard_pkt;
    223    
    224     udp = (struct udphdr *)((char *)ip + iphl);
    225    
    226     iov[0].iov_base = ip;
    227     iov[0].iov_len = iphl + sizeof(struct udphdr);
    228    
    229     ret = recvmsg(pkt_fd, &msg, 0);
    230     if (ret == -1)
    231     goto free_pkt;
    232    
    233 niro 1122 dprintf("<- bytes %d ", ret);
    234 niro 532
    235     if (ip_checksum((uint16_t *) ip, ip->ihl) != 0)
    236     goto free_pkt;
    237    
    238 niro 1122 dprintf("\n ip src %s ", ntoa(ip->saddr));
    239     dprintf("dst %s ", ntoa(ip->daddr));
    240 niro 532
    241     if (ntohs(ip->tot_len) > ret || ip->protocol != IPPROTO_UDP)
    242     goto free_pkt;
    243    
    244     ret -= 4 * ip->ihl;
    245    
    246 niro 1122 dprintf("\n udp src %d dst %d ", ntohs(udp->source),
    247     ntohs(udp->dest));
    248 niro 532
    249     if (udp->source != htons(cfg_remote_port) ||
    250     udp->dest != htons(cfg_local_port))
    251     goto free_pkt;
    252    
    253     if (ntohs(udp->len) > ret)
    254     goto free_pkt;
    255    
    256     ret -= sizeof(struct udphdr);
    257    
    258     free(ip);
    259    
    260     return ret;
    261    
    262     free_pkt:
    263 niro 1122 dprintf("freed\n");
    264 niro 532 free(ip);
    265     return 0;
    266    
    267     discard_pkt:
    268 niro 1122 dprintf("discarded\n");
    269 niro 1297 packet_discard(dev);
    270 niro 532 return 0;
    271     }